Hello all,
This is my entry for the SeaPhotography Contest by 
The animal is a nudibranch, the Nembrotha kubaryana. Some call it the Neon slug because of the vibrant colors.
The biggest ones can be up to 12 cm!
I took this picture a couple of years ago in the Philippines and this is the unedited version, straight out of the camera.
Olympus E-PL5 - 60mm macro lens - Inon D2000 Strobe
F/8 - Iso 400 - 1/60 sec